Pump for gaseous working fluids



Dec. 14,* 1948, R. LlscoMB 2,455,133

- PUMP FOR GAsEoUs WORKING FLUIns Filed Feb. 11,v 1944 y 5 sheets-sheet1 3a @HCI 3 Ii Il Inventor Dec. 14, 1948. R.`| 1P'scoMB PUMP FORGASEOUS-WORKING FLUIDS Filed Feb. 11,' 1944 5 Sheets-Sheet 2 Inventorjocom A ttor y Dec. 14, 1948. R. LlPscoMB PUMP FORYGASEOUS WORKINGFLUIDS 5 sheets-sheet :s

Filed' Feb. 11, 1944 Inventor se om Y mul Dec. 14, 1948. R, LlpscoMB2,456,133

` PUMPl FOR GAsEoUs WORKING FLUIDs Y Filed Feb. 11, 1944 5 Sheets-Sheet4 I n uentor Atto ey R. LIPSCOMB PUMP FOR GASEOUS WORKING FLUIDS ,Dern14, 194s.

5 Sheets-Sheet 5 Filed Feb. 11, 1944 Inventor E L b/U 3 CL 0127/5 AitorPatented Dec. 141, 1948 PUMP FOR GASEOUS `WORKJNG FLUIDS RobertLipscomb, Norton-on-Tees, England, assignor to Imperial ChemicalIndustries Limited,

a corporation of Great Britain Application February 11, 1944, Serial No.521,956 In Great Britain February 15, 1943 (Cl. ZBO-4) 1l Claims.

'Ihis invention relates to 'pumps for gaseous working fluids of the typecomprising a casing and one or more flexible bands forming a wall orwalls of one or more working chambers, the said band or bands beingsubjected to bending in such a manner that wave-like deformations travelunidirectionally along it or them from one end to the other. In a deviceof this kind, having a single band ii the wave crests maintain contactwith a wall of the casing and the edges also only very slightly clearthe casing, the casing wall and each wave of the band, i. e. the portionfrom one crest to the next, form a working chamber which is isolatedfrom the rest of the space within the device and which travels from oneend of the casing to the other and will therefore positively displaceany iiuid within it; by providing an inlet and an outlet communicatingwith the chamber at the respective ends of the device, the devicebecomes a positive pump. With a single band use may be made of the walland therefore oi the working chambers on one side only oi the band, or,ii the crests Contact with the walls on opposite'sides of the band usemay be made of the chambers on both sides of the band. A device having aplurality of bands will operate similarly as regards the spaces betweenthe bands provided that the crests oi one band maintain contact withanother band or bands; in general the crests oione band will bemaintained in contact with the crestsof the adjacent bands, so thatsymmetrical working chambers are formed. A multi-band device may alsomake use of the space between one outermost band and adjacent wall orbetween both outermost bands and adjacent walls, provided the crestsmaintain contact with this wall or walls.

In a known pump of this type, the working chamber is formed by aone-piece 'liexible tube, one side of which forms the band to which thewave-like Amovement is imparted. In this construction, however, parts ofthe tube are subjected to severe alternating bending stresses.

In other known pumps of this type the opposing walls oi the operatingchamber are separate, onewall being a wall oi the casing or a bandexecuting unidirectional wave-like movement and the other being aseparate band executing unidirectional wave-like movement. In thesemachines, however, in the forms already known, either there are rubbingsurfaces exposed to the working fluid, or the amplitude of the waves inthe bands is not maintained throughout the length of the bandsufhciently for crests or troughs of the waves to remain in ycontactwith the opposing surface of the working chamber. Where such contact isnot maintained the pump ceases to be positive, though a certain dynamicpumping effect may be obtained more particularly in the case of liquids.

The object of the present invention is to provide apositive-displacement pump of the type hereinbefore dened of greatereiciency than the known pumps of this type and which moreover isparticularly suitable for operating with noxious gaseous iiuids.

The pump of the present invention comprises a casing, and one or moreflexible plates which are subjected to bending in such a manner thatwave-like deformations travel unidirectionally along it or them from oneend to the other with `points of maximum displacement in the plate orplates in contact with the wall or walls of the casing and/or with eachWave in a plate out of phase with but in contact with the wave oppositeto it in each adjacent plate, thereby causing the plate or plates toform one or more working chambers with a wall of the casing and/orbetween adjacent plates; this is achieved according to the invention byapplying oscillatory movements to the plate or plates at intervalsthroughout its or their length by means of rods projecting into theworking space of the casing through gas tight seals and reciprocated bymeans outside the casing, or by applying an oscillatory movement to oneend of the plate or plates and so tapering the plate or plates inthickness and/or width that each wave in a plate maintains contact withthe wall of the casing and/or with the wave opposite to it in eachadjacent plate.

It is to be observed that since the invention makes use of a flexibleplate or plates, the severe bending stresses inherent in the use of aflexible tube or tubes are avoided, but that against this there must bea very slight clearance at the edges of the plate or plates, past whichthere will be slight leakage into or out of the working chamber. In viewof the gas tight seals for the operating rods used in the invention,this leakage is unimportant. The invention further makes it possible forthe casing itself to be used as one of the ducts for the fluid beingpumped, for instance the outlet, thus simplifying the construction.

By the term wave used herein is meant two consecutive half waves.

The arrangement may be such that an uninterrupted succession of thewave-like deformations of the plate or plates is maintained during theoperation of the pump. s

lcent plates.

The invention Will now be illustrated by Way of example by reference tothe accompanying drawings in which Figure l is a longitudinal secn tionof one form of pump. Figure 2 is a transverse section on the line AA ofFigure l, Figure 3 is a longitudinal section of another form of pump,Figure 4. is asection on `the line lBB of `Figure 3, and Figure is aplan view of the plates in Figure 3.

Referring to Figures 1 and 2, reference numeral I denotes a bed plate towhich are attached two parallel channel members 2 which form the sidesof the working chambers. Between these channel members six plates, 3a,3b, 3c, 3d, =3e, 3f, are mounted so that there is a small clearancebetween their edges and thechannel members. At one end the plates arerigidly secured by bolts 4 (only one of which is seen in Figure l) andare spaced apart by sleeves 5 on the bolts. The plates 3a, 3c, 3e, aresecured between sleeves 6 onsthe rods l, 8, 9 and I and are perforatedso that thereis a clearance between them and the sleeves -on the rodsII, I2 and I3. Similarly, the Aplates 3b, 3d and 3f are secured betweenthe sleeves 6 on the rods II, I2, i3 and lll, and are perforated toclear the sleeves on the rods l', 8, 9 arid-Ill. The rods l to I 4 whichpass through holes inthe bed plate sea-led by metallic bellows I5,` areconnected to cross heads i5 which are givena reciprocating motionthrough the connecting rods Il which are operated by eccentrics -I-B'onthe shafts lf2. The phases of the eccentrics are arranged to give a wavemotion to the plates, such that the waves in each plate are completelyout of phase with the waves in adjacent plates. The amplitudes of motionare such that, as shown, the wave crests in each plate are maintained incontact from the line of the rods 'l to that of the rods 1I0, so thatexcept for leahages past the edge clearances and the clearances roundthe sleeves on the rods l' to l, closed working chambers travel insuccession from one end to the other of the plates in the direction tothe right in Fig. l, andv inthe example illustrated only the workingchambers between the plates are used. The bed plate is provided with acover plate 2G, the gase ous fluid entering the working chambers throughtherectangular-sectioned duct 2i and being discharged into the casingconstituted by the bed plate vand the cover plate Ztl, thence leavingthrough the pipe 22.

In the pump shown in Figures 3, 4 and 5, the plates 3a, 3b, 3c, 3d, 3eand 3f are tapered in Widthfrorn the inlet end to the outlet end of theworking chambers and the channel members Ziconverge so as to leave asmall clearance be* :tween them and the edges of the plates throughouttheir length. Plates 3a, 3c and 3e are secured between sleeves E5 on therods la, 'Ib and lc, and are perforated so that they clear the sleeves 6on the rods IIa, Ilb, and IIc. Similarly, the plates 3b, 3d and 3f aresecured between sleeves fI'on-the rods Ila, IIb, IIc, and are perforatedso that they clear the sleeves on the rods la, 7b and 1c. The rods la,lb and 'lc are reciprocated .in phase with each other and completely outof phase withA the rods IIa, Hb and IIc, so that the waves generated ineach plate are completely out of phase with the waves generated in adja-`Beyond the rods l the wave motion in the plates is free. Consequentlythe energyl imparted by the plates to the fluid being pumped must comefrom the supply imparted to the plates by the rods and the energy leftin the plates will diminish from the inlet end to the outlet end; therewill also be a small additional loss due to external and internalfriction. If

therefore the section of the plates remained constant, the amplitude ofthe Wave motion would diminish from inlet to outlet, but this iscompensated according to the invention, by diminishing the section ofthe plates from inlet to outlet, for instance by tapering them. Thedegree of taper is chosen with respect to rate of fluid flow required sothat the amplitude of the waves generated in the plates remainssubstantially constant throughout the lengths of the plate. Itwill beevident that this form of the invention is only suitable where apredetermined and substantially constant rate of uid flow is required.Instead of tapering the Width of the plates, the thickness of the platesmay be tapered and the Width maintained luniform or a combination oftapering width and thickness may be employed.

'1. A pump comprising a casing, at least one flexible plate therein,rods yprojecting into the working space of the casing through gas-tightseals, and attached to the plate at intervals throughout its length,means for reciprocating the said rods to cause wave-like deformations totravel unidirectionally along the plate from the one end to the otherwith points of maximum displacement in the plate in contact with atleast one wall ofthe casing so as to form a pumping space between saidplateand said wall, and an inlet to and an outlet from said casing.

2. A pump comprising a casing, a plurality of flexible plates therein,to each of which are attached at intervals throughout its length, rodswhich project cut of the working space of the casing through gas-tightseals, kmeans for reciprocating the said rods to cause Wave-likedeformations to travel unidirectionally along the plate from one end tothe other with each wave in the plate out of phase with but in Contactwith the wave opposite to it in leach adjacent plate so as to fornipumping space between said plates, and an inlet to and an outlet fromsaid casing.

'3. A pump comprising a casing, a plurality of flexible plates therein,means adapted to apply oscillatory movements to one end of each plateand to cause wave-like deformations to travel unidirectionally along theplate from one end to the other, with each wave in the plate out ofphase with the wave'opposite to it inthe adjacent plates, each platebeing tapered so as to maintain each wave in it in contact with theopposite waves in .the adjacent plates, an inlet to said casing, and anoutlet from said casing.

4. A pump comprising a casing, at least one flexible plate therein,means adapted to apply .oscillatory movements to one end of each plateand so cause wave-like deformations to travel unidirectionally along theplate from one end to the other, each plate being tapered so as tomaintain each wave in contact with at least one wall of the casing, aninlet to said casing and an outlet from said casing.

5. A pump comprising a casing, aplurality of flexible plates therein, toeach of which are attached at intervals throughout its lengths, rodswhich project out of the working space of the cas.. ing`throughgas-tight seals7 means for reciprocating l'the said rods tocause wave-like deformations to travel unidirectionally along the platefrom one end. to the other with points of maximum displacement in theplate in Contact with points of maximum displacement in the adjacentplates, an

inlet to said casing, and yan outlet from said casing.

6. A pump comprising a casing, a plurality of flexible plates therein,means adapted to apply.

oscillatory movements to one end of each plate and so cause wave-likedeformations to travel unidirectionally along the plate from one end tothe other, each plate being tapered so as to maintain points of maximumdisplacement in it in contact with points of maximum displacement in theadjacent plates, an inlet to said casing, and an outlet from saidcasing.

'7. A pump comprising a casing, a plurality of exible plates therein,means adapted to apply oscillatory movements to one end of each plateand so cause wave-like deformations to travel unidirectionally along theplate from one end to the other, with each wave in the plate out ofphase with the wave opposite to it in the adjacent plates, each platebeing tapered in width so as to maintain each wave in it in contact withthe opposite wave in the adjacent plates, an inlet to said casing, andan outlet from said casing.

8. A pump comprising a casing, a plurality of exible plates therein,means adapted to apply oscillatory movements to one end of each plateand so cause wave-like deformations to travel unidirectionally along theplate from one end to the other, each plate being tapered in width so asto maintain points of maximum displacement in it in contact with pointsof maximum displacement in the adjacent plates, an inlet to said casing,and an outlet from said casing.

9. A pump comprising a casing, an inlet to and an outlet from saidcasing, a plurality of exible plates in said casing, to each of whichare attached near the inlet end of the pump, rods which project out ofthe casing through gas-tight seals, means for reciprocating the saidrods to cause wave-like deformations to travel unidirectionally from theinlet edge to the outlet edge of the plate with each wave out of phasewith the wave opposite to it in the adjacent plates, each plate beingtapered in width towards its outlet edge so as to maintain each wave init in contact with opposite waves in adjacent plates.

10. A pump comprising a casing, an inlet communicating with said casingthrough a rectangular port, a plurality of flexible plates within saidcasing, anchored near one of their ends in spaced relationship in theinlet port, means adapted to apply oscillatory movement near the saidanchored end of each plate and so cause Wave-like deformations to travelunidirectionally along the plate to the other end, with each wave in theplate out of phase with the wave opposite to it in the adjacent plates,each plate being tapered in width towards the said other end to maintaineach wave in the plate in contact with the opposite wave in the adjacentplates, and an outlet leading from said casing near the narrower ends ofthe plates.

11. A pump comprising a casing, an inlet communicating with said casingthrough a rectangular port, a plurality of flexible plates Within saidcasing, anchored near one of their ends in spaced relationship in theinlet port, to each of which plates are attached throughout its length,rods which project out of the casing through gas-tight seals, meansoutside the casing adapted to reciprocate the said rods and causewave-like deformations to travel unidirectionally from the anchored endof the plate to the other end thereof, with points of maximumdisplacement in the plate in contact with points of maximum displacementin the adjacent plates, and an outlet leading from said casing near theends of the plates remote from the inlet port.

ROBERT LIPSCOMB.

REFERENCES CITED The following references areof record in the le of thispatent:

UNITED STATES PATENTS Number Name Date 1,922,196 Butler Aug. 15, 19332,152,241 Coons Mar. 28, 1939 2,241,975 Bennett May 13, 1941 2,244,418Bennett June 3, 1941

